21853834 has 4 divisors (see below), whose sum is σ = 32780754. Its totient is φ = 10926916.

The previous prime is 21853831. The next prime is 21853889. The reversal of 21853834 is 43835812.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15578809 + 6275025 = 3947^2 + 2505^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21853834.

It is not an unprimeable number, because it can be changed into a prime (21853831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5463457 + ... + 5463460.

Almost surely, 2^21853834 is an apocalyptic number.

21853834 is a deficient number, since it is larger than the sum of its proper divisors (10926920).

21853834 is a wasteful number, since it uses less digits than its factorization.

21853834 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10926919.

The product of its digits is 23040, while the sum is 34.

The square root of 21853834 is about 4674.8084452735. The cubic root of 21853834 is about 279.5820038588.

The spelling of 21853834 in words is "twenty-one million, eight hundred fifty-three thousand, eight hundred thirty-four".